In Brief
Ultrafast Data Transmission Via Light
KIT scientists from a team around Prof. Dr Jürgen Leuthold encoded 26 terabit per second on a single laser beam and transmitted it over a distance of 50 kilometres. Then, the data also was successfully decoded. This is the largest quantity of data ever transmitted via a laser beam. The process developed at the KIT allows the transferral of the content of 700 DVDs within one second only.
This new optical-electric decoding process is based on the fact, that such maximum data quantities initially are calculated purely in an optical manner to break down the large amount of data to smaller bit rates, which then can be further processed electrically. The initial optical reduction of bit rates is necessary, since electronic processing does not take place at a data rate of 26 terabit per second.
For this record-breaking data encoding process the team around Leuthold uses the so-called orthogonal frequency-division multiplexing (OFDM) scheme. The process is being successfully used for many years now in mobile communications and is based on mathematical routines (Fast Fourier Transformation). Leuthold, head of the Institute of Photonics and Quantum Electronics and of the Institute of Microstructure Technology at the KIT, places emphasis on the fact that, "the trick was to make the process not just a thousand times faster but nearly a million times faster for data processing at 26 terabit per second." "Ultimately, the ground-breaking idea was the optical transformation of the mathematical routine." At the same time, it was revealed that calculation in the optical range is not only extraordinarily fast but also very energy efficient, since energy is required only for the laser and a few process steps.
